Underwater versus conventional endoscopic mucosal resection for colorectal lesions: a systematic review and meta-analysis

Abstract

Background and study aims Underwater endoscopic mucosal resection (UEMR) for colorectal polyps has been reported to have good outcomes in recent studies. We conducted a systematic review and meta-analysis comparing the effectiveness and safety of UEMR to conventional EMR (CEMR). Methods A comprehensive search of multiple databases (through May 2020) was performed to identify studies that reported outcome of UEMR and CEMR for colorectal lesions. Outcomes assessed included incomplete resection, rate of recurrence, en bloc resection, adverse events (AEs) for UEMR and CEMR. Results A total of 1,651 patients with 1,704 polyps were included from nine studies. There was a significantly lower rate of incomplete resection (odds ratio [OR]: 0.19 (95 % confidence interval (CI), 0.05–0.78, P = 0.02) and polyp recurrence (OR: 0.41, 95 % CI, 0.24–0.72, P = 0.002) after UEMR. Compared to CEMR, rates overall complications (relative risk [RR]: 0.66 (95 % CI, 0.48–0.90) (P = 0.008), and intra-procedural bleeding (RR: 0.59, 95 % CI, 0.41–0.84, P = 0.004) were significantly lower with UEMR. The recurrence rate was also lower for large non-pedunculated polyps ≥ 10 mm (OR 0.24, 95 % CI, 0.10–0.57, P = 0.001) and ≥ 20 mm (OR 0.14, 95 % CI, 0.02–0.72, P = 0.01). The rates of en bloc resection, delayed bleeding, perforation and post-polypectomy syndrome were similar in both groups (P > 0.05). Conclusions In this systematic review and meta-analysis, we found that UEMR is more effective and safer than CEMR with lower rates of recurrence and AEs. UEMR use should be encouraged over CEMR.

Underwater vs Conventional Endoscopic Mucosal Resection of Large Sessile or Flat Colorectal Polyps: A Prospective Randomized Controlled Trial

“…Several meta-analyses have reported the superior outcomes of UEMR over CEMR regarding en bloc resection rates, [18][19][20][21] which is refuted in the most recent meta-analysis by Chandan et al 17 for polyps >20 mm in size. However, the generalizability of these results can be questioned because different study designs were included in these metaanalyses.…”

“…15,16 Five recent meta-analyses across a broad lesion size range have addressed the efficacy of UEMR in comparison to CEMR and have shown an overall superior en bloc resection rate for UEMR compared to CEMR. [17][18][19][20][21] However, these metaanalyses included studies of different designs, thereby diminishing the quality of evidence. One randomized controlled study has shown the superior efficacy of UEMR over CEMR regarding the R0 resection rate for colorectal polyps between 10 and 20 mm in diameter.…”

Cold versus hot polypectomy/endoscopic mucosal resection–A review of current evidence

“…Another alternative in cases of polyps reaching the size of the applied snare but need to be en bloc resected, is underwater EMR which can lead to a higher proportion of R0 en bloc resections in these cases, which has been shown in several meta‐analysis. 22 , 54 …”

Modified endoscopic mucosal resection techniques for treating precancerous colorectal lesions

“…A pooled analysis showed that U-EMR achieves higher en bloc resection rate (odds ratio [OR] 1.61, 95%CI 1.02-2.53; P=0.04) and lower rate of recurrence/residual adenoma (OR 0.18, 95%CI 0.07-0.46; P<0.01) [ 26 ]. Subsequently, 4 updated meta-analyses were published [ 28 - 31 ]. Kamal et al [ 28 ], demonstrated a significant benefit of U-EMR in terms of en bloc resection (risk ratio [RR] 1.16, 95%CI 1.08-1.26; P<0.001, complete resection rate confirmed by histology (RR 0.75, 95%CI 0.57-0.98; P=0.03), as well as local recurrence (RR 0.26, 95%CI 0.12-0.56; P<0.001).…”